1. Field of the Invention
The present invention relates to a hybrid vehicle having an engine and a motor.
2. Description of the Related Art
For vehicles such as automobiles, for the purpose of seeking improvement in fuel consumption economy and reduction of exhaust gas amount, there is proposed a hybrid vehicle having a motor for providing auxiliary power, in addition to a gasoline engine.
Japanese Unexamined Patent Application Publication No. 2003-080956 discloses an engine unit for a starter, having an engine, a motor, a belt stepless speed changer, etc. In this engine unit, a drive pulley is mounted on a crank shaft of the engine and a length of belt is wound around this drive pulley and a driven pulley. The driven pulley is operably coupled to a drive shaft of a speed reducing drive mechanism via a centrifugal clutch. Further, the motor is mounted between the outer circumference of a clutch outer member as a driven side member of the centrifugal clutch and the inner circumference of a centrifugal clutch accommodating section (see e.g. FIG. 3). With the above-described arrangement in operation, the driving power of the engine is transmitted to the rear wheels via the belt stepless speed changer and the drive shaft of the speed reducing drive mechanism, etc. When the traveling load of the vehicle is large, the motor is also driven in addition to the above and the driving power of the motor is transmitted to the rear wheels. And, the regenerative energy generated at the time of speed reduction and braking is collected via the motor.
Further, Japanese Unexamined Patent Application Publication No. 2010-261544 and Japanese Unexamined Patent Application Publication No. 2003-307270 disclose hybrid systems that can be mounted in a work machine capable of traveling, such as a tractor, a backhoe, a multi-purpose work vehicle, a riding automobile, etc. and that are configured to transmit the driving powers of an engine and a motor generator to a belt stepless speed changer mechanism (CVT).
In the hybrid system disclosed in Japanese Unexamined Patent Application Publication No. 2010-261544, the crank shaft of the engine is connected to an input member of a multiple-disc clutch and an output member of this clutch is connected to the drive shaft of the belt stepless speed changer mechanism; and there is provided an electric generator having a rotor rotatable therewith on the outer circumference side of the clutch housing of the clutch. This hybrid system has a normal mode in which driving is provided by the engine, an assist mode in which the driving is provided by the engine and the electric generator, an EV mode in which the driving is provided by the electric generator, and a regenerative mode in which the electric generator is braked for regeneration.
In the hybrid system disclosed in Japanese Unexamined Patent Application Publication No. 2003-307270, the crank shaft of the engine is connected to an input member of a multiple-disc clutch and an output member of this clutch is connected to one end of a drive shaft of the belt stepless speed changer mechanism and the other end of the drive shaft is connected to the electric generator.
Further, conventionally, in a driving apparatus mounted in a traveling vehicle such as a tractor, a backhoe, a multi-purpose work vehicle, a riding automobile, etc., as disclosed in Japanese Unexamined Patent Application Publication No. 2011-132937, a propelling shaft (crank shaft) of the engine is connected to an input member of a centrifugal clutch and an output member of the centrifugal clutch is connected to a drive shaft of a belt stepless speed changer mechanism (CVT) so as to transmit a traveling driving power thereto.
And, an example of hybrid system capable of driving a driving apparatus mounting such belt stepless speed changer mechanism by a motor generator also, is disclosed by Japanese Unexamined Patent Application Publication No. 2010-261544.
According to the technique of Japanese Unexamined Patent Application Publication No. 2010-261544, a propelling shaft (crank shaft) of the engine is connected to an input member of a multiple-disc clutch via a damper and an output member of this clutch is connected to a drive shaft of a belt stepless speed changer mechanism. And, there is provided an electric generator (motor generator) having a rotor rotatable therewith on the outer circumference side of the clutch housing of the clutch. This hybrid system has a normal mode in which driving is provided by the engine, an assist mode in which the driving is provided by the engine and the electric generator, an EV mode in which the driving is provided by the electric generator, and a regenerative mode in which the electric generator is braked for regeneration (see second embodiment).
Further, an example of a driving apparatus for a traveling vehicle having two kinds of clutches mounted between an engine and a speed changer that can be set to a non-transmitting state is disclosed in Patent Document 3.
According to the technique disclosed in this Japanese Unexamined Patent Application Publication No. 2008-126702, a driving apparatus for a traveling vehicle includes an engine, a speed changer that can be set to a non-transmitting state, and a drive unit mounted between the engine and the speed changer and having a motor (power generator), and the power of at least one of the engine and the motor is transmitted to wheels via the speed changer and an output member of this speed changer, wherein the drive unit includes an input shaft connected to the engine, an output shaft connected to the speed changer, a coast clutch configured to disconnectably connect the input shaft and the output shaft and connected to the motor, a one-way clutch mounted parallel with the coast clutch and configured to transmit the rotation of the input shaft to the output shaft, but not to transmit the rotation of the output shaft to the input shaft, and a hydraulic pump driven by the output shaft for controlling engagement/disengagement of the coast clutch. The coast clutch is rendered into a locked state at the time of occurrence of no hydraulic pressure generation in the hydraulic pump (see claim).
And, according to the technique of this Japanese Unexamined Patent Application No. 2008-126702, the technique allows vehicle traveling by the engine alone or by the motor alone, or by the engine and the motor. The technique allows start and traveling by the motor alone, electric power charging at the time of start of the engine by the motor and start of the engine during traveling by the motor and speed reducing operation, charging during engine driving and speed reducing, as well as an engine braking operation during speed reduction, etc.